Gram-negative Haemophilus influenzae bacteria

This photograph depicts the colonial morphology displayed by Gram-negative Haemophilus influenzae bacteria, which was grown on a medium of chocolate agar, for a 24 hour time period, at a temperature of 37°C.

Invasive disease caused by Haemophilus influenza type-b can affect many organ systems. The most common types of invasive disease are pneumonia, occult febrile bacteremia, meningitis, epiglottitis, septic arthritis, cellulitis, otitis media, purulent pericarditis, and other less common infections such as endocarditis, and osteomyelitis.